1. Field of the Invention
The principles of the invention relate generally to pipelined information processing, and more particularly, to the pipelined processing of packet header information.
2. Description of Related Art
Routers receive data on a physical media, such as optical fiber, analyze the data to determine its destination, and output the data on a physical media in accordance with the destination. Routers were initially designed using a general purpose processor executing large software programs. As line rates and traffic volume increased, however, general purpose processors could not scale to meet these new demands. For example, as functionality was added to the software, such as accounting and policing functionality, these routers suffered performance degradation. In some instances, the routers failed to handle traffic at line rate when the new functionality was turned on.
To meet the new demands, purpose-built routers were designed with components optimized for routing. They not only handle higher line rates and higher network traffic volume, they also add functionality without compromising line rate performance.
A purpose-built router may include a number of input and output ports from which it transmits and receives information packets. A packet received at one port is directed to its appropriate output port based on an examination and processing of the packet's header information, which includes an indication of the packet's destination. A high-performance router must accordingly examine and process the header information at a high speed.